A motor-vehicle door latch has an outside release lever whose end is normally moved vertically to unlatch the vehicle door. The door handle, however, is typically movable horizontally so that a natural pull on the handle first unlatches the door and then pulls it open.
A standard actuating mechanism for such a door has a pivotal link lever connected to the handle and connected in turn via a vertical link rod to the latch-release lever. Thus the horizontal movement of the handle is converted into a vertical movement of the rod and of the free end of the latch-release lever.
With this known system in an accident the door is frequently popped open. This happens when a blow from the side into the door pushes in the door panel and the outside door handle, whose base plate is mounted in the door so that it pivots about a horizontal axis. This forcible rotation of the door handle raises the link rod so that the latch-release lever is lifted and the latch opened. The cause of this is that a pushing in of the door is effective to bend in and effectively shorten the link rod or the entire outside-handle mechanism is pivoted about a horizontal axis to raise the link-rod.
A motor-vehicle door latch is also known from German patent document 3,345,588 of J. Johnson (claiming priority of U.S. application 450,061 of Dec. 15, 1982) with a support element mounted on the door, a linearly movable actuating mechanism connected with the support element, and a release lever that is pivotal on the support element and that is set up to actuate the door latch. The mechanism has a linearly movable cam element with a spiral actuating formation and a release lever having a cam opening through which passes the cam element and which has a cross section corresponding to that of the cam element. Furthermore a mechanism is provided effectively connecting the cam element with the actuating device such that a linear movement of the cam element moves the cam element via the actuating mechanism linearly through the cam opening and moves the release lever to actuate the door latch. This known mechanism is difficult to assembly and has problems in that the linear movement of the cam element is produced by a spiral-shaped section in a cam opening. Thus substantial friction and wear must be allowed for so that the conversion of the handle movement into a pivotal movement of the release lever is normally unsatisfactory.